Method and device for left atrial appendage occlusion

ABSTRACT

A device and method for obliterating or occluding a body cavity or passageway, in particular, the left atrial appendage of a patient&#39;s heart. The procedure can be carried out intraoperatively, but is preferably carried out percutaneously by use of a delivery catheter to position an occluding device adjacent a patient&#39;s left atrial appendage. The occluding device may prevent the passage of embolic or other material to or from the left atrial appendage by volumetrically filling the appendage, closing the opening of the appendage with an occluding member, or pulling the tissue around the opening of the appendage together and fixing it in a closed state.

BACKGROUND

Embolic stroke is the nation's third leading killer for adults, and is amajor cause of disability. There are over 80,000 strokes per year in theUnited States alone. The most common cause of embolic stroke emanatingfrom the heart is thrombus formation due to atrial fibrillation. Atrialfibrillation is an arrhythmia of the heart that results in a rapid andchaotic heartbeat that produces lower cardiac output and irregular andturbulent blood flow in the vascular system. There are over five millionpeople worldwide with atrial fibrillation, with about four hundredthousand new cases reported each year. Atrial fibrillation is associatedwith a 500 percent greater risk of stroke due to the condition. Apatient with atrial fibrillation typically has a significantly decreasedquality of life due, in large part, to the fear of a stroke, and thepharmaceutical regimen necessary to reduce that risk.

For patients who have atrial fibrillation and develop atrial thrombustherefrom, the clot normally occurs in the left atrial appendage (LAA)of the heart. The LAA is a cavity which looks like a small finger orwindsock and which is connected to the lateral wall of the left atriumbetween the mitral valve and the root of the left pulmonary vein. TheLAA normally contracts with the rest of the left atrium during a normalheart cycle, thus keeping blood from becoming stagnant therein, butoften fails to contract with any vigor in patients experiencing atrialfibrillation due to the discoordinate electrical signals associated withAF. As a result, thrombus formation is predisposed to form in thestagnant blood within the LAA. Blackshear and Odell have reported thatof the 1288 patients with non-rheumatic atrial fibrillation involved intheir study, 221 (17%) had thrombus detected in the left atrium of theheart. Blackshear JL, Odell JA. Appendage obliteration to reduce strokein cardiac surgical patients with atrial fibrillation. Ann Thorac.Surg., 1996.61(2):755-9. Of the patients with atrial thrombus, 201 (91%)had the atrial thrombus located within the left atrial appendage. Theforegoing suggests that the elimination or containment of thrombusformed within the LAA of patients with atrial fibrillation wouldsignificantly reduce the incidence of stroke in those patients.

Pharmacological therapies for stroke prevention such as oral or systemicadministration of warfarin or the like have been inadequate due toserious side effects of the medications and lack of patient compliancein taking the medication. Invasive surgical or thorascopic techniqueshave been used to obliterate the LAA, however, many patients are notsuitable candidates for such surgical procedures due to a compromisedcondition or having previously undergone cardiac surgery. In addition,the perceived risks of even a thorascopic surgical procedure oftenoutweigh the potential benefits. See Blackshear and Odell above. Seealso Lindsay BD. Obliteration of the left atrial appendage: A conceptworth testing. Ann Thorac. Surg., 1996.61(2):515. What has been neededis a less invasive system and method for containment or elimination ofthrombus formation in the LAA of patients with atrial fibrillation. Thepresent invention satisfies these and other needs.

SUMMARY

The present invention is directed to a device and method forobliterating or occluding a body cavity or passageway. Specifically, theinvention is directed to a device and method for obliterating oroccluding the left atrial appendage of a patient's heart, preferably bypercutaneous methods which obviate the need for invasive surgicalprocedures. One purpose of obliterating or occluding a body cavity orpassageway, or particularly the left atrial appendage of a patient, isto prevent the passage or egress of embolic material into thebloodstream of a patient.

One embodiment of an apparatus having features of the invention has anoccluding member having an outer rim or periphery disposed around theperimeter of the occluding member, with the outer rim configured tosealingly engage a surface of a body cavity. The apparatus also has ananchoring device or means which is secured to the occluding member. Theanchoring device or means may include an adhesive between the outerperiphery and an inside surface of a body cavity, a suture or sutureswhich are engaging the outer periphery of the occluding member and theinside surface of the body cavity, or the like. The anchoring device ormeans serve to secure the outer periphery to a surface of a body cavityor passageway so as to prevent the passage of embolic material or othermaterials therethrough.

In another embodiment, an apparatus having features of the invention mayhave an occluding member and a retention member secured to the occludingmember. The retention member is configured to engage and attach to asurface of a body cavity and maintain a position of the occluding memberto sealingly engage the inside surface of the body cavity and preventthe passage of embolic material or the like therethrough. In embodimentsof the apparatus which are intended to occlude a patient's LAA, theoccluding member will typically be a frame structure of a high strengthmaterial such as stainless steel, a shape memory or pseudoelastic alloy,such as NiTi alloy, or a suitable composite material. The framestructure has a barrier or mesh material disposed over it and preferablysecured to it to act as a barrier to the passage of embolic material orfluids. The frame structure serves to support the barrier or meshmaterial in an outwardly expanded state to substantially occupy at leasta portion of the cross section of a body cavity or passageway withinwhich it is disposed. The mesh or barrier material can be any suitablematerial for preventing the passage of fluids, embolic material or othermaterial suspended in fluids. Typical examples of suitable materials forthe barrier include a Nylon or Dacron mesh. Preferably, the barrier ormesh material is made from PTFE or ePTFE having a pore size of up toabout 0.04 inches, preferably up to about 0.005 inches. Other suitablematerials may include polyurethanes, polyamides, polyethylenes or thelike. The outer rim or periphery of the occluding member is preferablymade of a soft polymer material which facilitates a seal between theouter rim and the inside surface of the body cavity. The outer rim mayhave a radial hoop of a metal or other high strength material orcomposite to provide outward radial pressure on the inside surface ofthe body cavity, and to maintain the shape of the outer rim. Theoccluding member may have a transverse dimension of about 0.5 to about 5cm, preferably about 1 to about 2 cm.

The retention member secured to the occluding member may have anysuitable configuration which maintains the position of the occludingmember within the body cavity or passageway so as to form at least asubstantial seal with the surface therein and prevent the passage ofembolic material. Preferably, the retention member is an expandablemember configured to engage the inside surface of the body cavity orpassageway. The expandable member may be an expandable cylindricallyshaped wire structure, typically with linked metallic elements which arecapable of self expansion from a constrained state. The expansion memberis preferably made from a shape memory or pseudoelastic alloy such asNiTi, or the like, but may also be made from high strength materialssuch as stainless steel, MP35N and other suitable materials. Theexpandable member can be covered with a polymer fabric or mesh to act asa buffer between the metallic elements of the expandable member and theinside surface of the body cavity within which it is disposed. The outersheath may be made of Dacron, Nylon, TFE, PTFE, ePTFE, polyurethane orthe like.

In another embodiment of a device having features of the invention, theretention member may be a tissue penetrating shaft which is designed topenetrate an inner wall of a body cavity, preferably the fundus of abody cavity, and be mechanically secured thereto. In a particularembodiment of the tissue penetrating shaft, the distal extremity of theshaft has a helically shaped extension which screws into the tissue ofthe wall of a body cavity and is thereby mechanically secured thereto.The tissue penetrating shaft may have a length of about 0.5 to about 7cm, preferably about 1 to about 4 cm, and more preferably about 1.5 toabout 3 cm. An alternative embodiment of the tissue penetrating shaftwould include radially extending members from the distal end of a shaftin place of or in conjunction with the helically shaped extension. Theradially extending members serve to center the shaft within the bodycavity or passageway, and also to engage the tissue of the body cavityor passageway to prevent axial movement of the shaft and occludingmember. The shaft can have up to about 20 radially extending members,but preferably has about 3 to about 10 radially extending members.

Preferably a method of closing off or blocking a body cavity, inparticular a patient's LAA, is performed in a non-invasive orpercutaneous manner. Delivery of an occluding device is typicallycarried out via a Mullin's trans-septal approach whereby a trans-septalcatheter and needle are delivered percutaneously from a point ofinsertion into the right femoral vein under local anesthesia. Single orbiplanar flouroscopy can be used to image the trans-septal catheterduring the procedure and guide the distal end of the catheter to thedesired site. It is therefor advantageous for at least portions of thetrans-septal catheter and LAA occlador device to be at least partiallyradiopaque. The trans-septal catheter is advanced through the rightfemoral vein into the right atrium and positioned adjacent the coronaryseptum. The needle is advanced from the distal end of the catheter andpunctures the septum in a desired location. The trans-septal catheter isthen advanced over the needle through the septum and into the leftatrium. Preferably, the distal end of the trans-septal catheter or anyother type of delivery catheter used for this procedure has a distal tipportion with angulation of up to about 40°, preferably about 10° toabout 30° with respect to a longitudinal axis of the catheter disposedimmediately proximal to the angled distal tip portion. An angleddischarge axis of the distal end of the delivery catheter facilitatesaccess to the opening of a patient's left atrial appendage. The needleassembly is then withdrawn leaving an open lumen within the trans-septalcatheter with access to the left atrium. The LAA occluder device is thenadvanced from the proximal end of the trans-septal catheter to thedistal end thereof and into or adjacent the patient's LAA. Once theoccluder device is properly positioned, it can be deployed. Properpositioning of the occluder device can be determined by flouroscopy,intracavity or extracorporeal ultrasonic imaging, includingtransesopheogeal ultrasonic imaging (TE Echo), CT, MRI or any othersuitable imaging technique.

Alternatively, the procedure to position and deploy the occluding membermay be performed intraoperatively in a stand alone procedure or inconjunction with another procedure which provides access to the LAA orother desired passageway or cavity.

In another embodiment of an apparatus having features of the invention,a device for occluding a body cavity or passageway has an occlusive bodyconfigured to at least partially fill the volume of the left atrialappendage or other desired cavity or passageway of a patient. In oneaspect of the invention, the occlusive body is an inflatable memberwhich is detachably secured to a delivery catheter and configured to fitwithin, or preferably substantially fill the LAA of a patient. Theinflatable member may also have a retention member secured to it whichserves to engage the inner surface of a body cavity or passageway andmaintain the position of the inflatable member relative to the bodycavity or passageway. The inflatable member is configured to engage theinside surface of the LAA to prevent the passage of fluid or embolicmaterial therefrom. Embolic material may be fluids, particulatesuspended in fluids such as blood clots, gas bubbles, solid tissue orthe like. In addition to or in lieu of the retention member, theinflatable member or balloon may have a ribbed surface which is shapedso as to engage the trebecula of the inside surface of a patient's LAA.The ribs should extend radially about 1 to about 4 mm from the nominalsurface of the inflatable balloon, and should be spaced about 3 to about8 mm from each other, and can be circumferential, longitudinal orspirally configured. The inflatable balloon may also include materialsdesigned to induce fibrosis, such as Dacron®. Typically, the inflatableballoon is inflated within the LAA by injection of saline, silicone, orother suitable material.

In another aspect of the invention, the occlusive body may be a coiledmember or members, in particular, one or more helical metallic coilshaving either a straight shape in a relaxed state or anotherconfiguration such as random, helical, convoluted shape in the relaxedstate. When the coil is introduced into the cavity or passageway of thepatient, it can assume the shape of a coiled mass that serves to occludethe cavity or passageway. The occlusion may result from the mechanicalpacking of the cavity or passageway, or may be augmented bythrombogenesis caused by the occlusive member. The coils may have alength of about 1 to about 20 cm and may have a diameter of about 0.01to about 0.02 inches. The material from which the coils are wound canhave a cross sectional dimension of about 0.001 to about 0.05 inches,preferably about 0.002 to about 0.006 inches. The occlusive coil can bemade from any suitable material including stainless steel, NiTi alloy,or suitable radiopaque metals or composites such as gold, platinum,tantalum or iridium or alloys thereof. In an alternative embodiment, theocclusive coil is secured to a covering element or occluding memberwhich is disposed in the ostium or opening of a body cavity to preventthe passage of embolic material therethrough.

In yet another aspect of the invention, the occlusive body may be apolymer mass or mass of other biocompatible material that can beintroduced or injected into a body cavity or passageway, in particular,into the left atrial appendage of a patient. The polymer mass may beinjected in a flowing fluid or gel form, and then harden to anon-flowing solidified or hardened mass with the passage of time or withelevated temperatures. Examples of suitable polymeric materials wouldinclude various epoxies, hydrogels, and adhesives, including polymerssuch as n butyl cyanoacrylate, polyisocyanate (polyurethaneprepolymers), moisture curing silicone, synthetic polymers innon-aqueous but water miscible solvents (DMSO), latex, fibrin, andcollagen type IV.

In general, the occlusive body would be deployed or delivered to the LAApercutaneously, as with the trans-septal approach discussed above.However, it may also be deployed intraoperatively during an invasiveprocedure, or ancillary to another procedure which gives access to theLAA. The occluding mass could also be secured to a covering element orbarrier that is disposed within the ostium or opening of a body cavityto prevent the passage of occlusive or embolic material therethrough.

Another device having features of the invention is used to close a bodycavity or LAA off permanently at its opening by pulling the openingclosed and mechanically fixing the opening in a closed state. Anapparatus for closing off a cavity or LAA of a patient having featuresof the invention generally has an elongate shaft with proximal anddistal ends and a lumen within the shaft. Movably or slidably disposedwithin the lumen of the shaft are a plurality of tissue attachmentmembers which also have proximal and distal ends. The tissue attachmentcan be accomplished by mechanical grasping or hooking, but can also bevacuum or suction actuated. The attachment by the tissue attachmentmembers can be self activating or initiating upon contact with orpenetration of tissue, or may be controlled from the proximal end ofelongate members which are secured to the tissue attachment members andare also at least partially slidably disposed within the lumen of theelongate shaft. The elongate members may contain or house electricalconductors, fiber optic cables, or control lines operatively connectedto the tissue attachment members to transmit the appropriate energy,signal or force to the tissue attachment members in order to initiateand maintain tissue attachment, or to collect and transmit an image ofthe site.

The tissue attachment members and distal ends of the elongate membersattached thereto are configured to extend beyond the distal end of theelongate shaft which can be positioned adjacent to tissue to be closedoff. In this way, the tissue attachment members can extend distally andat an angle to a longitudinal axis of the elongate shaft and makecontact with tissue and attach thereto. The tissue attachment membersmay then be retracted into the distal end of the elongate shaft so as topull the various portions of the tissue together and close the cavity oropening of the LAA. The device preferably includes a closure memberwhich is generally configured as a retaining ring which is slidablydisposed over the elongate members and configured to restrain tissuecollected and pulled together by the tissue attachment members uponretraction. The closure member may also be a staple which secures thetissue of the opening. The tissue of the annular edge of the cavitywhich has been collected and pulled together by the tissue attachmentmembers may also be fixed or secured in the closed state by suturing,bonding with a biocompatible polymer adhesive, stapling, tissue weldingor the like. Tissue welding suitable for use with the invention may becarried out with laser energy applied to the closed tissue. Laser energymay be supplied by Nd:YAG or HO:YAG laser types. Various configurationsof surgical staples could be used to fix or secure the closed tissue ofthe body cavity or LAA, including the type disclosed by U.S. Pat. No.4,603,693 to Conta et al. which is incorporated by reference herein inits entirety and which discloses a device for deploying surgicalstaples.

The apparatus for closing a body cavity is generally delivered in anon-invasive, preferably percutaneous manner. An elongate deliverycatheter having an inner lumen is percutaneously delivered such that adistal end of the delivery catheter is adjacent the opening of thepatient's body cavity to be closed off. The closure device or apparatusfor closing off a cavity or LAA of a patient is advanced distally withinthe delivery catheter from the proximal end thereof. The closure deviceis then advanced out of the distal end of the delivery catheter, and thetissue attachment members and elongate members advanced distally fromthe elongate shaft so that the tissue attachment members are in contactwith the tissue of the opening of the body cavity to be closed. Thetissue attachment members are then activated so as to attach to thetissue. The tissue attachment members are then retracted proximally backinto the elongate shaft and the closure member advanced distally,preferably by distal movement of an elongate push shaft disposedproximal to the closure member and slidably disposed over the elongatemembers of the closure device. The closure member is advanced until itis disposed over the tissue of the cavity opening that is attached tothe tissue attachment members and confines the tissue of the cavityopening so as to close off the cavity. The tissue attachment members canthen be deactivated and withdrawn, and the closure device and deliverycatheter withdrawn proximally to complete the procedure.

These and other advantages of the invention will become more apparentfrom the following detailed description when taken in conjunction withthe accompanying exemplary drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of an embodiment having features of theinvention with an occluding member and a retention member.

FIG. 2 shows an end view of the apparatus of FIG. 1 in partial section.

FIG. 3 shows a longitudinal cross sectional view of the apparatus ofFIGS. 1 and 2.

FIG. 3A shows a perspective view of an apparatus having features of theinvention.

FIG. 3B shows an elevational view in partial section of the apparatus ofFIG. 3A.

FIG. 4 shows an elevational view of an apparatus having features of theinvention in a deployed state within a body cavity.

FIG. 5 shows an elevational view of an apparatus having features of theinvention in a deployed state within a body cavity.

FIG. 6 shows a perspective view of an apparatus for sealing off a bodycavity having features of the invention.

FIG. 7 shows an elevational view in partial section of an apparatus forsealing off a body cavity having features of the invention.

FIG. 8 shows a transverse cross-sectional view of the apparatus of FIG.7 taken along lines 8--8.

FIG. 9 shows a schematic view of a patient's heart with a trans-septalcatheter deployed through the septum and a delivery catheter andapparatus for sealing off a body cavity disposed therein.

FIG. 10 shows a schematic view of a patient's heart in partial sectionwith a delivery catheter disposed within the opening of the LAA.

FIG. 11 shows a magnified view of the delivery catheter distal end andthe LAA of a patient of FIG. 10 with an apparatus for sealing off a bodycavity partially deployed within the LAA.

FIG. 12 shows the apparatus for sealing off a body cavity of FIG. 11fully deployed within a LAA.

FIG. 13 shows an elevational view of a device for occluding a bodycavity having features of the invention.

FIG. 14 shows a transverse cross sectional view of the device foroccluding a body cavity of FIG. 13 taken along lines 14--14.

FIG. 15 shows a device for occluding a body cavity having features ofthe invention deployed within a LAA.

FIG. 16 shows a device for occluding a body cavity having features ofthe invention deployed within a LAA.

FIG. 17 shows a LAA being occluded by a method having features of theinvention.

FIG. 18 shows a LAA occluded by method having features of the invention.

FIG. 19 shows a LAA occluded by method having features of the invention.

FIG. 20 is an elevational view of an apparatus for closing an interiorbody cavity of a patient in partial section having features of theinvention.

FIG. 21 is a schematic view of an apparatus for closing an interior bodycavity of a patient in contact with tissue of a LAA.

FIG. 22 is a schematic view of an apparatus for closing an interior bodycavity of a patient in contact with tissue of a LAA.

FIG. 23 shows a LAA which has been closed by a method having features ofthe invention.

DETAILED DESCRIPTION

FIGS. 1-3 show an embodiment of an occluding device 10 having featuresof the invention where an occluding member 11 is secured to a retentionmember 12 that is arranged to fix the occluding member in a desiredposition within a body passageway or cavity. The occluding member 11generally has disc shape with an outer rim 13 around the perimeter of aframe structure 14 which supports a barrier 15. The outer rim 13 can becircular or polygonal, or any other shape that is suitable forconforming to the inside surface of a body cavity. A hub 16 can belocated near the center of the occluding member 11 which serves toconnect the retention member 12 to the occluding member, in addition toother functions. The outer rim 13 is typically made from a soft polymermaterial 17 which permits flexibility of the outer rim and facilitatessealing of the outer rim against the inside surface of a body cavity orpassageway. The barrier 15 can be a thin mesh or film of material whichserves to block the passage of material within an area surrounded by theouter rim 13. The barrier 15 can be secured to the outer rim 13 alongits entire perimeter 18 in order to achieve a complete seal therebetweenand can be molded into the outer rim 13 or bonded thereto by a suitablemethod such as gluing, welding, sewing or other suitable method. Theouter rim 13 is at least partially supported by the frame structure 14which connects the outer rim and the hub. The frame structure 14 can bemade from one or more elements of high strength material such asstainless steel or MP35N, or may preferably be made from shape memory orpseudoelastic alloys such as NiTi. Preferably, the frame structure 14 ismade from a material which can be self expanding from a constrainedconfiguration so that the occluding device 10 can be delivered to thedeployment site in a low profile an flexible configuration whichfacilitates percutaneous delivery. Preferably a radial hoop 21 iscontained within the soft polymer material 17 of the outer rim 13 andserves to maintain the annular shape of the outer rim and facilitateradial expansion of the outer rim from a constrained position orconfiguration. The radial hoop 21 may be isolated within the softpolymer material 17 of the outer rim 13, or may be connected to at leastsome the elements 22 of the frame structure 14, in order to havestronger mechanical joint between the outer rim and the frame structure.The radial hoop 21 is shown in a substantially circular configuration,but may also be polygonal or otherwise suitably shared, and may haveconnections or joints spaced thereon to facilitate contraction orfolding of the device for non-invasive delivery.

In addition to connecting the retention member 12 and the occludingmember 11, the hub 16 may serve to house a rotational coupling 23 whichis connected to the proximal end 24 of a tissue penetrating shaft 25within the retention member. The rotational coupling 23 allows thetransfer of torque to the tissue penetrating shaft 25 which preferablyhas a helically shaped extension or distal extremity 26 which isconfigured to screw into tissue and be mechanically fixed thereto.Longitudinal movement of the tissue penetrating shaft 25 relative to theretention member 12 and hub 16 may be prevented by sizing a lumen 27 ofthe retention member which contains the tissue penetrating shaft suchthat the helically shaped extension 26 at the distal end is too large topass through the lumen and the proximal end 24 of the tissue penetratingshaft is prevented from passing through the lumen by the rotationalcoupling attached thereto. The rotational coupling 23 may also beconfigured to be longitudinally captured by the hub 16 but still berotatably disposed therein.

FIGS. 3A and 3B depict an alternative embodiment of an occluding device10 having an occluding member 11 and a retention member 12. Theretention member 12 has a shaft 28 and radially extending members 29extending radially from a proximal end of the shaft. The radiallyextending members 29 serve to anchor the shaft 28 and the occludingmember 11 by engaging the tissue surrounding the occluding device.Preferably, the radially extending members are self expanding from aconstricted state and are made of a pseudo elastic alloy such as NiTi,or a high strength material such as stainless steel. Although it ispreferable for the radially extending members 29 to be self expandingfrom a constricted state, they may also be expanded by use of shapememory properties or a radial outward force as would be provided by aninflatable balloon or the like. The shaft 28 can be a single element ormade of multiple elements, and can be made from the same materials asthe radially extending members or different materials such as polymersor polymer composites. The radially extending members 29 have aproximally directed bias at their radial extremities 29A so that themembers readily fold down and move easily in a distal direction duringinsertion of the occluding device 10, but spring outward andaggressively engage surrounding tissue upon movement in a proximaldirection. This configuration of the radially extending members 29allows easy insertion into a body cavity, but prevents egress of thedevice 10 in and outward or proximal direction.

FIG. 4 depicts an occluding device 30 similar to that depicted in FIGS.1-3 deployed within the left atrial appendage 31 of a patient. An outerrim or periphery 32 of the occluding device 30 is disposed adjacent theopening 33 of the left atrial appendage 31 in a position which allowsfor a substantial seal of the outer rim against the inside surface 34 ofthe LAA. A helically shaped distal extremity 35 of a tissue penetratingshaft 36 has been screwed into the wall tissue of the LAA and ismechanically secured thereto. A retention member 38 maintains theposition of an occluding member 41 in a substantially perpendicularorientation with respect to a longitudinal axis of the LAA 42.

FIG. 5 depicts an occluding device similar to that depicted in FIGS. 1-4deployed within a LAA 51 of a patient similar to what is shown in FIG.4. The structure of an occluding member 52 of the embodiment as shown inFIG. 5 differs from that shown in FIG. 4 in that a barrier 53 and framestructure 54 of the embodiment of FIG. 5 protrudes proximally from aplane defined by an outer rim 55. This configuration may be useful forcertain morphologies of patient's LAAs. One object of the invention isto create a smooth surface outside the body passageway or cavity inorder to prevent turbulent flow or eddies of blood or other bodily fluidwithin the cavity or passageway. The alternative configuration of theoccluding device 50 shown in FIG. 5 may be useful in this regard.

FIG. 6 shows an alternative embodiment of an occluding device 60 whichhas an occluding member 61, a frame structure 62, a barrier 63 and aretention member in the form of an expandable member 65 which has linkedelements 66 that are preferably expandable from a constrainedconfiguration. The expandable member 65 is generally cylindrical inshape and can have a series of circumferential linked elements 66connected by links 68. Although FIG. 6 depicts the expandable member 65as a series of linked elements 66, those skilled in the art will realizethat a similar effect can be achieved with a single wire in a helicalconfiguration or a plurality of wires in a mesh or braidedconfiguration, or any other suitable configuration that can be selfexpanding from a constrained configuration or expanding with theapplication of heat or other form of energy or force. For example, theexpandable member 65 may be configured to be deployed by an outwardradial force delivered from within the expandable member. An inflatableballoon or the like could be used to exert such a force. The expandablemember is preferably secured to an outer rim 71 of the occluding member61 but may also be secured to the frame structure 62 directly orindirectly. The expandable member 65 can be self expanding from aconstrained configuration as can the occluding member 61 and the framestructure 62 and outer rim 71 thereof. The frame structure 62, outer rim71 and barrier 63 may have construction similar to that described abovewith regard to the similar elements of the embodiments depicted in FIGS.1-5.

Referring to FIG. 7, the expandable member 65 as shown in FIG. 6 mayalso have a sheath 72 disposed around it so as to act as a shieldbetween the expandable member and an inner surface of a patient's bodycavity or passageway. The sheath 72 may facilitate the sealing functionof the occluding member 61, but is primarily intended to prevent damageto either tissue on the inside surface of a body cavity or to the linkedelements 66 of the expandable member. The sheath 72 may surround all orpart of the expandable member 65 and may be made from a variety ofsuitable biocompatible materials such as Dacron®, Nylon, TFE, PTFE orePTFE. The sheath 72 may be a weave, braid, film or have any othersuitable configuration. Expandable member 65 may also be coated bydipping, spraying, or other suitable process with a friction reducingmaterial such as Teflon®, or with an active compound such as heparin.

FIG. 8 shows a transverse cross sectional view of the embodiment of FIG.7 taken at lines 8--8. The frame structure 62 has an axis or hub 73disposed at approximately the center of the frame structure which servesto connect the various radial elements 74 of the frame structure. Thehub 73 can have an independent structure that links the several elements74 of the frame structure 62 or it may be merely the terminus of thevarious frame structure elements and have a solid composition. In eitherstructure, the hub 73 preferably allows a constrained configuration ofthe occluding member 61 to facilitate percutaneous delivery of theoccluding device 60. The hub 73 may also have a lumen disposed thereinto allow passage of a guidewire of other guiding member. Preferably, thelumen would have a self sealing valve or gasket which prevents thepassage of fluid or embolic material once the guidewire or guidingmember is removed from the lumen.

Referring to FIG. 9, a schematic view of a patient's heart 80 in partialsection shows a trans-septal catheter 81 having a proximal end 82 and adistal end 83. The distal end 83 of the trans-septal catheter 81 isdisposed within a patient's heart 80 with the distal end 84 of adelivery catheter 85 extending from the distal end 83 of thetrans-septal catheter. The distal end 83 of the trans-septal catheter 81has breached the septum 86 of the patient's heart 80 and is disposedadjacent the opening of the patient's LAA 88. At the proximal end 82 ofthe trans-septal catheter 81 there is a Luer connector 91 coupled to ahemostasis valve 92 which prevents the egress of blood from a lumen 93of the trans-septal catheter 81. The proximal end 94 of the deliverycatheter 85 extends proximally from the hemostasis valve 92 and has aLuer connector 95 attached to the proximal extremity thereof. Theproximal end 96 of a plunger 97 extends from the Luer connector 95 ofthe delivery catheter. The proximal end 94 of the delivery catheter isarranged to allow rotational and axial movement of the plunger 97 whilepreventing blood or other bodily fluids from leaking between thedelivery catheter 85 and the plunger 97.

Referring to FIG. 10, a patient's heart 80 is shown in partial sectionwith the distal end 84 of a delivery catheter 85 disposed within the LAAopening 87. FIG. 11 is a magnified view of the LAA 88 shown in FIG. 10and the distal end of the delivery catheter 84, which is shown inpartial section, contains a plunger 97 which is slidably disposed withinan inner lumen 98 of the delivery catheter 85 and serves to apply axialforce in a distal direction on the collapsed occluding member 101disposed within the delivery catheter so as to force the occludingdevice 102 from the delivery catheter and deploy it. An occluding device102 having an expandable member 103 and an occluding member 101 securedthereto is partially deployed and extending from the distal end of thedelivery catheter 84 into the patient's LAA 88. The occluding device 102can also be guided into the patient's LAA 88 by use of an appropriateguidewire or guiding member.

FIG. 12 shows the occluding device 102 of FIG. 11 in a deployed statewithin the patient's LAA 88. An outer rim 104 of the occluding member101 is in substantial sealing contact with the inside surface 105 of theLAA 88. The expandable member 103 has expanded so as to contact theinside surface 105 of the LAA and secure the occluding device 102thereto and maintain the occluding member 101 in a substantiallyperpendicular orientation relative to a longitudinal axis 106 of the LAA88. A barrier 107 is disposed within an area bounded by the outer rim104 and is positioned to prevent the passage of embolic or othermaterial to or from the LAA 88. The distal end 108 of the plunger 97 isextending from the distal end of the delivery catheter 84 after havingpushed the occluding device 102 from the delivery catheter.

Referring to FIG. 13, an occluding device 110 having features of theinvention is shown. The occluding device 110 has a delivery catheter 111with a distal end 112, a detachment mechanism 113 disposed on the distalend of the delivery catheter and an occlusive body or inflatable member114 detachably secured to the detachment mechanism. The inflatablemember 114 has a proximal end 115 and a distal end 116 with the proximalend being attached to the detachment mechanism 113 and the distal endterminating at an end cap 117. The inflatable member 114 has an outsidesurface 118 that may contain a fibrosis inducing material such asDacron® or other similar materials. The inflatable member 114 may bemade from a fluid tight film of polymer material which can be eithercompliant or non-compliant. Preferably the inflatable member 114 is madefrom silicone, however, any suitable material such as polyethylene,polyurethane or PET can be used.

The detachment mechanism 113 can be activated by mechanical force or bydelivery of thermal or optical energy by a suitable conduit.Alternatively, the inflatable member can be pushed into the LAA from thedelivery catheter 111 by an elongate push member without the use of adetachment mechanism. The inflatable member 114 can be filled with agas, fluid or gel which is injected under pressure through the deliverycatheter 114 and into the inflatable member. Suitable fluids to injectwould include saline and silicone. The inflatable member 114 may also befilled with a polymer material that can be hardened. A fluid, gel orpolymer used to fill the inflatable member may contain contrast agentssuch as gold, tantalum, bismuth, barium sulfate or the like in order toimprove visualization under flouroscopy or x-ray imaging.

FIG. 14 is a transverse cross sectional view of the occluding device 110of FIG. 13 taken along lines 14--14. An optional inner shaft 121 isshown disposed within the inflatable member 114, preferably in aconcentric arrangement. The inner shaft 121 provides longitudinal axialsupport to the inflatable member 114 so as to maintain a longitudinaldimension of the inflatable member 114 when it is being inflated anddeployed. The inner shaft 121 may be solid or contain one or more lumensthat may or may not be in fluid communication with an inner lumen 122 ofthe inflatable member 114, and can be used for the passage of aguidewire or guiding member.

FIG. 15 depicts an alternative embodiment of an occluding device 110which consists of an inflatable member 114 similar to the inflatablemember of FIG. 13, shown substantially deployed, within a patient's LAA123. The inflatable member 114 has been at least partially filled with afluid, gas or gel within the patient's LAA 123 such that the outsidesurface of the inflatable member 118 is in contact with at least part ofthe inside surface 124 of the LAA. The inflatable member 114 can haverib members 125 which can mechanically interlock with the trebeculae 126of the inside surface of the LAA 124 or other surface irregularities ofthe inside surface of a patient's body cavity or passageway. The ribmembers 125 form a complete circumference of the inflatable member 114,but could also form a partial circumference, spiral configuration, orconsist of random projections on the surface of the inflatable member118. The rib members 125 should extend radially about 1 to about 4 mmfrom the nominal surface of the inflatable member 114, and arepreferably spaced about 3 to about 8 mm from each other. The rib members125 may be made from any suitable polymer material, but are preferablymade from the same material as the inflatable member, and are integrallymolded thereon, or bonded thereto with a heat weld or adhesive bondsuitable for bonding flexibly medical polymers. The inflatable member114 is depicted with the distal end of the delivery catheter 112 anddetachment mechanism 113 attached. As an alternative, or in addition tothe polymer rib members 125 shown in FIG. 15, barbs or hooks could besecured to the outside surface of the inflatable member 114 which areconfigured to engage the inside surface of a patient's LAA 124.Preferably, barbs or hooks disposed on the outside surface of theinflatable member and configured to engage the tissue of the insidesurface of a patient's LAA 124 would have a proximally directed bias attheir radial extremity so that the barbs would fold down and move easilyin a distal direction during insertion of the inflatable member 114, butwould spring outward and aggressively engage the tissue of the bodycavity upon movement in a proximal direction of the inflatable member.

FIG. 16 depicts an occluding device 110 consisting of an inflatablemember 114 which is shown deployed within a patient's LAA 123. Theembodiment of the inflatable member 114 shown in FIG. 16 has an optionalretention member 127 with a tissue penetrating shaft 128 which has aproximal 131 end and a distal end 132. A rotational coupling 133 isdisposed at the proximal end 131 of the tissue penetrating shaft 128 anda helically shaped extremity 134 is disposed at the distal end of theshaft 132. The helically shaped distal extremity 134 is shown deployedwithin and mechanically engaging wall tissue 135 of the LAA so as tosecure the inflatable member 114 and maintain its position within theLAA 123 of the patient.

FIG. 17 shows an alternative embodiment of an occlusive member 140consisting of a polymer mass 141 which has been injected or deliveredinto a patient's LAA 142. The distal end 143 of a delivery catheter 144has a lumen 145 therein which extends to a proximal end of the deliverycatheter which is in fluid communication with a source of pressurizedpolymer material. A source of pressurized polymer material 146 can beany type of pump or device capable of forcing a polymer fluid or gelinto the proximal end of the delivery catheter with sufficient pressureto force the polymer fluid or gel out the distal end 143 of the deliverycatheter 144 and into a patient's body cavity or passageway. Thedelivery catheter 144 may be positioned by the techniques discussedabove, e.g. the Mullins trans-septal approach or any other suitablemethod. Once the distal end of the delivery catheter 143 is disposedwithin a desired portion of the patient's LAA 142, the polymer mass 141may be injected to fill the cavity to the desired level. The LAA 142 canbe completely or partially filled with the polymer mass 141 which can beformulated to harden over time, with heat or remain in a fluid or gelstate. The distal end of the delivery catheter can optionally include anexpandable member which is used to substantially seal the deliverycatheter against the inside surface of the opening of the patient's bodycavity during the delivery of polymer material. The expandable membercan be an inflatable balloon or the like which are well known in theart.

Optionally, a retention member 127 having a tissue penetrating shaft 128or the like, such as shown in FIG. 16 with regard to the inflatablemember 114, may be deployed within the LAA 142 prior to injection of thepolymer mass 141 and captured thereby so as to secure the polymer masswithin the LAA. Alternatively, the polymer mass can be used to fill thepatient's LAA and surround and secure a deployed device as shown inFIGS. 4 or 5 in the patient's LAA 142.

Once a desired amount of polymer mass 141 has been injected into the LAA142, as assessed for example by TE Echo imaging, the delivery catheter144 may be withdrawn and the procedure terminated. Preferably the entireLAA 142 of a patient is filled with the polymer mass 141 as shown inFIG. 18 and hardens or gels to maintain its shape. It may be desirableto have the polymer mass 141 retain a soft compressible form aftersetting or hardening so that it is at least partially compliant with theconstrictive pumping action of a heart and resistant to fatigue as aresult thereof. A material used to form the polymer mass 141 may containcontrast agents such as gold, platinum, tantalum, bismuth or the like inorder to better visualize the deployment of the polymer mass underfluoroscopic or x-ray imaging.

Another alternative embodiment of an occlusive member 140 can be foundin FIG. 19 which shows an occlusive coil 147 which has been deployedwithin an LAA 142. The occlusive coil 147 as shown has assumed a randomconfiguration that is mechanically occluding the LAA 142 and which hasinduced clot and or fibrosis formation 148 which further facilitatesocclusion of the LAA 142.

An apparatus for closing off a body cavity or passageway 150 is shown inFIG. 20 which has features of the present invention. The apparatus 150has an elongate shaft 151 with an inner lumen 152 and a proximal end 153and a distal end 154. Slidably disposed within the inner lumen 152 ofthe elongate shaft 151 are at least two elongate members 155 which haveproximal ends 156 and distal ends 157 and have tissue attachment members158 disposed on the distal ends. An optional distal anchor member 161 isalso slidably disposed within the inner lumen 152 of the elongate shaft151 and preferably has a distal end 162 terminating with a helicalmember 163. The proximal end 153 of the elongate shaft 151 has aproximal control module 164 which seals the inner lumen 152 of theelongate shaft 151 and allows rotation and translation of the proximalends 156 of the elongate members 155 and the distal anchor member 161while maintaining a seal between said members to prevent leakage ofbodily fluids therefrom. The proximal control module 164 can optionallybe configured to control advancement and retraction of the elongatemembers 155 and control activation of the tissue attachment members 158.

FIG. 21 shows the apparatus for closing off a body cavity 150 of FIG. 20with the distal ends of the elongate members 157 and the tissueattachment members 158 extending distally from the distal end of theelongate shaft 154. The distal ends of the elongate members 157 areangled or deflected from a longitudinal axis 165 of the elongate shaft151 so as to engage tissue 166 of the opening 167 of the LAA 168 asshown. The elongate members 155 may be deflected by an abutment orangulation contained in the distal end of the elongate shaft 154, butare preferably preshaped in an angled configuration which manifests whenthe distal ends are freed of the constraint of the inner lumen 152 ofthe elongate shaft an allowed to assume their relaxed preshapedcondition. The helical member 163 at the distal end 162 of the distalanchor member 161 is engaged with the wall tissue 171 of the LAA 168 soas to provide an optional anchor that can be used to move the elongateshaft 151 relative to the distal anchor member 161 and give greatercontrol of the longitudinal axial movement of the elongate shaftrelative to the LAA opening 167. The tissue attachment members 158 areshown attached to the annular edge 172 of the LAA opening 167. Once thetissue attachment members 158 are attached, a closure member orretaining ring 173 may be advanced distally by applying axial force onan elongate push shaft 174 which draws the tissue attachment members 158and the tissue attached thereto closer together as shown in FIG. 22. Asthe closure member 173 is further advanced distally, the annular edge ofthe LAA 172 is drawn closed, and eventually, the annular edge of the LAAwill be completely closed into a closed state with the closure member173 surrounding and compressing the tissue of the annular edge as shownin FIG. 23. Once a closed state of the LAA is achieved, the tissueattachment members 158 may be detached, and the apparatus for closingoff a body cavity 150 withdrawn. One alternative method can have thetissue attachment members 158 drawn together by retracting themproximally into the distal end 154 of the elongate shaft 151 as opposedto distally advancing the closure member 173 with the elongate pushshaft 174. In this way, the annular edge of the LAA 172 can be drawninto a closed state within the distal end 154 of the elongate shaft 151at which point the annular edge may be fixed in the closed state by avariety of methods including suturing, tissue welding, the applicationof a suitable biocompatible adhesive, surgical staples or the like.

While particular forms of the invention have been described, it will beapparent that various modifications can be made without departing fromthe spirit and scope of the invention. Accordingly, it is not intendedthat the invention be limited, except as by the appended claims.

What is claimed is:
 1. A method of occluding a left atrial appendage ofa patient comprising:a) providing a device for occluding a body cavitycomprising:an occluding member, and a retention member secured to theoccluding member; b) providing a delivery catheter having a proximal endand a distal end; c) advancing the delivery catheter percutaneouslythrough the patient's vasculature to a chamber within the patient's leftatrium; d) advancing the distal end of the delivery catheter and thedevice for occluding a body cavity adjacent the left atrial appendage;and e) deploying the device for occluding a body cavity such that theoccluding member substantially obstructs the passage of embolic materialto and from the left atrial appendage.
 2. The method of claim 1 whereinthrombotic or fibrotic material is removed from the patient's leftatrial appendage prior to deployment of the device for occluding a bodycavity.
 3. The method of claim 2 wherein the thrombotic or fibroticmaterial is removed from the patient's left atrial appendage byaspiration through an aspiration lumen of a catheter having a port inthe distal end thereof in fluid communication with the aspiration lumenwhich is operatively connected at its proximal end to a vacuum source.4. The method of claim 1 wherein the retention member comprises anexpandable member configured to engage an inside surface of the leftatrial appendage and the device for occluding a body cavity is at leastpartially deployed by expanding the expandable member within the leftatrial appendage so as to engage at least a portion of an inner surfaceof the left atrial appendage.
 5. The method of claim 1 wherein theretention member comprises a tissue penetrating shaft configured topenetrate and be secured to tissue of the left atrial appendage and thedevice for occluding a body cavity is at least partially deployed bypenetrating the tissue of the left atrial appendage with the tissuepenetrating shaft such that the tissue penetrating shaft is mechanicallysecured thereto.
 6. The method of claim 1, wherein the retention membercomprises a shaft having at least one radially extending memberextending radially therefrom and configured to engage an inside surfaceof a patient's left atrial appendage and the device for occluding a bodycavity is at least partially deployed by expanding the at least oneradially expanding member from a constrained configuration so as toengage the tissue of the left atrial appendage.
 7. The method of claim 6wherein the at least one radially expanding member is comprised of apseudoelastic alloy which is self expanding from a constrainedconfiguration.
 8. A method of occluding a left atrial appendage as inclaim 1, wherein the occluding member comprises a self expandable frame.9. A method of occluding a left atrial appendage as in claim 8, furthercomprising a barrier on the frame.
 10. A method of occluding a leftatrial appendage as in claim 9, wherein the barrier has a pore size ofup to about 0.04 inches.
 11. A method of occluding a left atrialappendage as in claim 9, wherein the barrier comprises a polymerselected from the group consisting of Dacron, Nylon, TFE, PTFE, ePTFE,and polyurethane.
 12. A method of occluding a left atrial appendage asin claim 1, wherein the retention member comprises a self expandablewire structure.
 13. A method of occluding a left atrial appendage as inclaim 12, further comprising a polymer on the wire structure.
 14. Amethod of occluding a left atrial appendage as in claim 1, wherein thefirst advancing step comprises advancing the delivery catheter throughthe right femoral vein.
 15. A method of occluding a left atrialappendage of a patient, comprising the steps of:providing a deliverycatheter having a proximal end and a distal end, and a device foroccluding a body cavity thereon, the device comprising an occludingmember and a retention member secured to the occluding member; advancingthe delivery catheter into a chamber within the patient's left atrium;positioning the device for occluding a body cavity adjacent the leftatrial appendage; and deploying the device for occluding a body cavitysuch that the occluding member substantially obstructs the passage ofembolic material to and from the left atrial appendage.
 16. The methodof claim 15, wherein thrombotic or fibrotic material is removed from thepatient's left atrial appendage prior to deployment of the device foroccluding a body cavity.
 17. The method of claim 16, wherein thethrombotic or fibrotic material is removed from the patient's leftatrial appendage by aspiration through an aspiration lumen of a catheterhaving a port in the distal end thereof in fluid communication with theaspiration lumen which is operatively connected at its proximal end to avacuum source.
 18. The method of claim 15, wherein the retention membercomprises an expandable member configured to engage an inside surface ofthe left atrial appendage and the device for occluding a body cavity isat least partially deployed by expanding the expandable member withinthe left atrial appendage so as to engage at least a portion of an innersurface of the left atrial appendage.
 19. The method of claim 15,wherein the retention member comprises a tissue penetrating shaftconfigured to penetrate and be secured to tissue of the left atrialappendage and the device for occluding a body cavity is at leastpartially deployed by penetrating the tissue of the left atrialappendage with the tissue penetrating shaft such that the tissuepenetrating shaft is mechanically secured thereto.
 20. A method ofoccluding a left atrial appendage as in claim 15, wherein the occludingmember comprises a self expandable frame.
 21. A method of occluding aleft atrial appendage as in claim 20, further comprising a barrier onthe frame.
 22. A method of occluding a left atrial appendage as in claim21, wherein the barrier comprises a polymer selected from the groupconsisting of Dacron, Nylon, TFE, PTFE, ePTFE, and polyurethane.
 23. Amethod of occluding a left atrial appendage as in claim 21, wherein thebarrier has a pore size of up to about 0.04 inches.
 24. A method ofoccluding a left atrial appendage as in claim 15, wherein the retentionmember comprises a self expandable wire structure.
 25. A method ofoccluding a left atrial appendage as in claim 24, further comprising apolymer on the wire structure.
 26. A method of occluding a left atrialappendage as in claim 15, wherein the advancing step comprises advancingthe delivery catheter through the right femoral vein.
 27. A method ofoccluding a left atrial appendage as in claim 15, wherein the advancingstep comprises advancing the delivery catheter to the left atrialappendage intraoperatively.
 28. A method of occluding a left atrialappendage as in claim 15, wherein the device comprises a plurality oftissue engagement members, and the method further comprises the step ofengaging tissue with the tissue engagement members.
 29. A method ofoccluding a left atrial appendage as in claim 1, wherein the devicecomprises a plurality of tissue engagement members, and the methodfurther comprises the step of engaging tissue with the tissue engagementmembers.